A missing link in the evolution of the front claw of living scorpions and horseshoe crabs was identified with the discovery of a 390 million-year-old fossil by researchers at Yale and the University of Bonn, Germany.
The specimen, named Schinderhannes bartelsi, was found fossilized in slate from a quarry near Bundenbach in Germany, a site that yields spectacularly durable pyrite-preserved fossils — findings collectively known as the Hunsrück Slate. The Hunsrück Slate has previously produced some of the most valuable clues to understanding the evolution of arthropods – including early shrimp-like forms, a scorpion and sea spiders as well as the ancient arthropods trilobites.
Schinderhannes bartelsi. Credit: Steinmann Institute/University of Bonn
"With a head like the giant Cambrian aquatic predator Anomalocaris and a body like a modern arthropod, the specimen is the only known example of this unusual creature," said Derek Briggs, director of Yale's Peabody Museum of Natural History and an author of the paper appearing in the journal Science.
Scientists have puzzled over the origins of the paired grasping appendages found on the heads of scorpions and horseshoe crabs. The researchers suggest that Schinderhannes gives a hint. Their appendages may be an equivalent to those found in the ancient predatory ancestor, Anomalocaris — even though creatures with those head structures were thought to have become extinct by the middle of the Cambrian Period, 100 million years before Schinderhannes lived.
The fossil's head section has large bulbous eyes, a circular mouth opening and a pair of segmented, opposable appendages with spines projecting inward along their length. The trunk section is made up of 12 segments, each with small appendages, and a long tail spine. Between the head and trunk, there is a pair of large triangular wing-like limbs — that likely propelled the creature like a swimming penguin, according to Briggs. Unlike its ancestors from the Cambrian period, which reached three feet in length, Schinderhannes is only about 4 inches long.
A reconstruction of Schinderhannes bartelsi. Credit: Elke Groening
This finding caps almost 20 years of study by Briggs on the Hunsrück Slate. "Sadly, the quarry from which this fabulous material comes has closed for economic reasons, so the only additional specimens that are going to appear now are items that are already in collectors' hands and that may not have been fully prepared or realized for what they are," said Briggs.
Other authors of the paper are Gabriele Kühl and Jes Rust at the University of Bonn, Germany. Funding for the research was from the German Science Foundation and the Humboldt Foundation.
Derek Briggs http://www.peabody.yale.edu/contact/index.html
Peabody Museum of Natural History http://www.peabody.yale.edu/
background information on Anomalocaris http://paleobiology.si.edu/burgess/anomalocaris.html
Hunsrück Slate http://palaeo.gly.bris.ac.uk/Palaeofiles/Lagerstatten/Hunsruck/index.html
Article: Science (February 6, 2009)
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Is That A Real Patient Or A Junkie? Now There's An App For That
- How The Higgs Became The Target Of Run 2 At The Tevatron
- You Are Ready To Eat Insects If You Have These Characteristics
- Global 'Roadmap' Shows Where To Put Roads Without Costing The Earth
- How Neuroscience Is Being Used To Spread Quackery In Business And Education
- MOOCs: Learning About Online Learning, One Click At A Time
- Will We Meet ET Microbes On Mars? Why We Should Care Deeply About Them - Like Tigers
- "More precisely: you can say that you have a quantum of an EM wave *after* one combined creation/detection..."
- "What are you planning to do this Month? Here is the list of 200 free online courses that start..."
- "So in this representation every four vector is represented by a 4x4 matrix, but not every 4x4 matrix..."
- "If you look up a text on Quantum Electrodynamics you should find a Psi field for creating and destroying..."
- "You guessed alright, that is a page from the book...Cheers,T...."
- Geochronology and global context of the Charnian Supergroup
- Confirmation of a low pre-extensional geothermal gradient in the Grayback normal
- Scientists get set for simulated nuclear inspection
- Invisible blood in urine may indicate bladder cancer
- Sugar substance 'kills' good HDL cholesterol, new research finds